Phase identification is a process of discovering and recording the phase, e.g., from among the phases of three-phase electrical power, to which devices in an electrical distribution network are connected. Knowledge of phase use is important to an electric utility, and assists with functions such as load balancing, power distribution efficiency, smart grid analytics and others. Accordingly, a thorough knowledge of the topology of an electrical network, including knowledge of a phase to which electric meters, transformers and other devices are connected, is important for electrical grid operation.
Manual inspection may be performed to identify phase use by network devices. According to such techniques, electric meters may be inspected at their actual location, and their supply lines followed to the substation. Surveyors may thereby understand network topology and device phase use. However, difficulties in accurately following lines and the expense of such methods prevent their widespread use.